Personal safety practices

Remove jewelry, watches and rings

Tie hair back and avoid loose clothing

Do not play games in the shop

Be aware of other workers unsafe habits

List personal safety practices when working in the shop

Wear safety glasses at all times when in the shop area

Ask when not sure of any procedure

Wear non slip oil resistant soled leather shoes

Personal safety practices

Do not wear contact lenses

Do not hesitate to remove yourself from any unsafe environment

Understand the health risks of any chemicals that you are using

Personal safety practices

Do not work when intoxicated or taking medications that reduce your alertness

Do not work when you are over stressed or tired

Do not attempt to lift any heavy object without the proper tools or assistance

Personal safety practices

Do not work alone

Insure an instructor is present in the lab while you are working on any project.

Basic Electrical Theory

Define Electricity

The ability to perform “work” by moving electrons between atoms

Electron Movement

Heat, light or magnetism is created when electrons move from atom to atom

Alternator provides power for running vehicle

Alternator provides power for running vehicle

Where do electrons come from?

• Atoms!

What is an atom?

an Atom consists of:Electrons Protons and Neutrons

Protons and neutronsmake up the nucleus

Like charges repel each other but the neutrons “glue”the protons in the nucleus

Electrons are repelled from each other, but attracted to the protons. Energy (in the form of centrifugal force) keeps the electrons moving in their orbital shell.

What is a Volt?

Voltage

Electromotive Force (EMF)

the electrical pressure that forces electrons to move from atom to atom

Voltage is present when there is a difference in electrical pressure

For Electrons to move between atoms

There must be a force to make them leave

or a “difference” in electrical pressure

These are “balanced” atoms

The electrons have no reason to leave the atom

An unbalanced atom is an “ion”

This ion has a negative charge

This ion has a positive charge

Opposite

Opposite Charges

Opposite Charges Attract

Similar

Similar charges

Similar charges repel

For current to flow there must be a positive

AND

a negative potential

To have voltage you must have a difference in electrical pressure

Positive ionNegative ion

The electromotive force between ions is called

VOLTAGE

Know your Voltmeter

• http://us.fluke.com/VirtualDemos/80_series_V_demo.swf

Lab #3

Using the Voltmeter